1. Field of the Invention
The present invention relates to a method of processing a wafer and dividing the resultant wafer into individual devices.
2. Related Art
A wafer a plurality of devices are formed on the front surface which are partitioned by streets, is ground at a rear surface thereof into a predetermined thickness and then diced by cutting along the streets to divide the wafer into individual devices, which are utilized for various kinds of electronic machines (refer to JP-A-2004-228133, for example).
However, a cutting blade rotating at a high speed cuts into the streets of the wafer for dicing, and the devices is likely to be chipped due to a breaking force of the blade, and consequently the die strength of the devices constituting the wafer lowers to cause the quality of the device to decrease. Especially, it has been demanded to set thickness of the wafer extremely small, i.e. to not larger than 100 μm, or not larger than 50 μm in recent years, and accordingly the mentioned strength of the devices has become an important problem.
In a dicing operation, it is necessary to align the blade with each street accurately and then cutting the streets one by one, so that the efficiency of the cutting operation becomes low. Especially, when the sizes of the devices are small with the number of the streets to be cut is large, cutting all the streets takes a considerably much time. This causes the productivity of the devices to be greatly reduced.
Therefore, an object to be solved by the present invention is to enable a wafer to be divided into individual devices efficiently in dicing a wafer without causing the quality of the devices to lower.